The goals of the research project are to devise a stereo- and regiospecific synthesis of chemically stable, cyclobutanone analogs of penicillins for testing as inhibitors of penicillinase as antibiotics, as inducers of penicillinase as antigens toward heterogeneous penicillin induced antibodies and as probes (i.e. iodo analogs) for crystallographic characterization of the penicillinase and transpeptictase receptors.